Box lattice support girder

Abstract

A support element for use with shotcreting to line tunnel walls with cement includes four rods secured to outer surface portions of quadrilateral reinforcement members. The longitudinal axis of pairs of adjacent rods each lie in a plane such that adjacent planes are normal to one another. Optionally, side braces may be secured to an outer surface or to an inner surface of adjacent rods.

Description

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of Provisional Application Serial No. 60/354,541 filed Feb. 5, 2002, in the name of James E. Marianski for “Box Lattice”. Provisional Application Serial No. 60/354,541 is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a support girder or support element used to help resist underground construction loads during tunneling and, more particularly, to a box lattice support element having four rods secured in a predetermined relationship to one another by quadrilateral reinforcement members and, optionally, including side braces.

[0004] 2. Brief Description of the Prior Art

[0005] In the New Austrian Tunneling Method (NATM), lattice girders or lattice support elements serve some of the basic functions as steel arch supports. More particularly, after the preparatory work is completed, the support elements are built in to support the roof and/or walls of the tunnel. The support elements, in general, include a plurality of spaced elongated metal rods held in spaced relationship, usually by welding or wiring the rods to stiffening members or spiders. For extended lengths of support elements, the ends of the support elements are secured together by flanges provided at the ends of the support elements and securing them together, e.g., by a nut and bolt assembly, to form a lattice grid. Cement is applied to the walls of the tunnel through the support elements and to the support elements by a technique known in the art as shotcreting.

[0006] The support elements provide a more efficient bond with the shotcrete strength because they essentially have no shaded areas. More particularly, the shotcrete passes through the support elements readily reducing the possibility of unconsolidated shotcrete areas behind the support element which provides for a more even and essentially void-free concrete layer. Examples of prior art support elements are disclosed in U.S. Pat. Nos. 4,335,556 to Arnold and 5,054,964 to Salzmann et al.

[0007] The Arnold patent, in general, discloses a support element having three or more exterior rods arranged in a polygon cross section and connected to one another by stiffening elements. Each stiffening element includes a number of cross struts bent in their centers and inclined with respect to the rods. The Salzmann patent, in general, discloses a support element having three exterior rods arranged in a triangular cross section. Each of the three rods is connected by a triangularly-shaped stiffening element, with each of the three rods connected to a corresponding corner of the triangularly-shaped stiffening element. A limitation of the presently available support elements, e.g., of the type disclosed in the Arnold and Salzmann patents, is the complexity of the stiffening members.

[0008] As can be appreciated by those skilled in the art, it would be advantageous to provide a support element that has less complicated stiffening members joining the exterior rods.

SUMMARY OF THE INVENTION

[0009] The present invention relates to an article, e.g., a support element, having a plurality of longitudinal members, e.g., from rods such as round stock or rebar, secured in special relationship to one another by one or more reinforcement members, hereinafter also referred to as “quadrilateral reinforcement member” or “QRM”.

[0010] The first rod, second rod, third rod, and fourth rod of the support element are preferably spaced apart from one another with the first rod and the second rod each lying in a first imaginary plane, the second rod and the third rod each lying in a second imaginary plane, the third rod and the fourth rod each lying in a third imaginary plane, and the first rod and the fourth rod lying in a fourth imaginary plane. In one non-limiting embodiment of the invention, the support element has at least one set of opposed imaginary planes parallel to one another, e.g., the first and third imaginary planes or the second and fourth imaginary planes parallel to one another. In another non-limiting embodiment of the invention, the support element has both sets of opposed imaginary planes parallel to one another, e.g., the first and third imaginary planes and the second and fourth imaginary planes parallel to one another. In a further non-limiting embodiment of the invention, the first imaginary plane is spaced from and substantially parallel to the third imaginary plane; the second imaginary plane is spaced from and substantially parallel to the fourth imaginary plane; and the first and third imaginary planes are each substantially perpendicular to the second imaginary plane and the fourth imaginary plane. With the foregoing arrangement, the support element may have a trapezoidal, a rectangular, a square, or other cross-sectional shape having one set or two sets of parallel imaginary planes or sides.

[0011] The first QRM preferably has a hollow square cross-sectional shape, but the actual shape of the first QRM is largely dependent on the cross-sectional shape defined by the four rods. The first QRM preferably has a first segment, a second segment connected perpendicularly to one end of the first segment, a third segment connected perpendicularly to one end of the second segment, and a fourth segment joining the other end of the first segment to the other end of the third segment.

[0012] In a non-limiting embodiment of the invention, the first QRM is positioned inside the first, second, third, and fourth rods, substantially perpendicular to the first imaginary plane and third imaginary plane, and preferably at an angle with respect to the second imaginary plane and the fourth imaginary plane. A second QRM may also be provided inside the first, second, third, and fourth rods, wherein the second QRM is spaced away from the first QRM or positioned immediately adjacent to the first QRM. The second QRM is also positioned substantially perpendicular to the first imaginary plane and third imaginary plane, and preferably forms the same angles with respect to the second imaginary plane and the fourth imaginary plane as the first QRM. The first and second QRMs may be defined as a QRM pair or reinforcement group with the distance between the first and second QRMs at the second imaginary plane being different than the distance between the first and second QRMs at the fourth imaginary plane. In another non-limiting embodiment, the second QRM is positioned substantially perpendicular to the second and fourth imaginary planes and preferably form an angle with the first and third imaginary planes.

[0013] Additional QRMs or QRM pairs may also be added, with each subsequent QRM or QRM pair spaced from the other QRM pairs in a repetitious, symmetric manner.

[0014] The QRM pairs described above are preferably bounded by the first imaginary plane, the second imaginary plane, the third imaginary plane, the fourth imaginary plane, the first rod, the second rod, the third rod, and the fourth rod. Although not limiting to the invention, external side braces or support members may also be added to the rods for added strength. For example, a side brace can be positioned parallel to the first imaginary plane and connected to the first rod and the second rod. A second side brace can be positioned parallel to the third imaginary plane and connected to the third rod and the fourth rod. The side braces can be positioned between the first QRM and second QRM in a QRM pair or can overlap the first or second QRM of the QRM pair.

[0015] One advantage of the present invention is that the square or rectangular cross-sectional configuration of the four rods permits forces acting on the support element to transfer through the four rods linearly along the rods and through the QRMs and QRM pairs. The four rod configuration, preferably spaced apart to form a square or rectangular cross section, along with the QRM pairs and, optionally, side braces, provides similar strength symmetry or the same strength symmetry, depending on the support element design, regardless of the orientation of the support element, and is generally a lighter alternative to other commercially available support elements. The present invention can also be constructed from lighter materials, thus making the present invention less expensive to manufacture. Moreover, by adding more QRM pairs, or by adding side braces to an exterior of the four rods, or by overlapping interior QRM pairs with additional exterior side braces, the support element according to the present invention may be modified to resist heavier loads.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG. 1 is an end view of a non-limiting support element incorporating features of the invention;

[0017] FIG. 2 is a side view of the support element shown in FIG. 1;

[0018] FIG. 3 is a top view of the support element shown in FIG. 1;

[0019] FIG. 4 is an end view of another non-limiting support element incorporating features of the invention;

[0020] FIG. 5 is a side view of the support element shown in FIG. 4;

[0021] FIG. 6 is an orthogonal view of the support element shown in FIG. 4;

[0022] FIG. 7 is an end view of still another non-limiting support element incorporating features of the invention;

[0023] FIG. 8 is a side view of the support element shown in FIG. 7; and

[0024] FIGS. 9-12 are views similar to the view of FIG. 8 showing additional non-limiting features of support elements incorporating features of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0025] As used herein, spatial or directional terms, such as “inner”, “outer”, “left”, “right”, “up”, “down”, “horizontal”, “vertical”, and the like, relate to the invention as it is shown in the drawing figures. However, it is to be understood that the invention can assume various alternative orientations and, accordingly, such terms are not to be considered as limiting. Further, all numbers expressing dimensions, physical characteristics, and so forth, used in the specification and claims are to be understood as being modified in all instances by the term “about”. Accordingly, unless indicated to the contrary, the numerical values set forth in the following specification and claims can vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Moreover, all ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein. For example, a stated range of “1 to 10” should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more and ending with a maximum value of 10 or less, e.g., 5.5 to 10.

[0026] In the following discussion, unless indicated otherwise, like numbers refer to like components.

[0027] With reference to FIGS. 1-3, there is shown a non-limiting support girder or support element 30 incorporating features of the invention. The support element 30 includes rods 32-35 arranged in a fixed relationship to one another by a plurality of reinforcement members; reinforcement member 37 is shown in FIG. 1 and reinforcements members 37-41 are shown in FIGS. 2 and 3. As can be appreciated, the invention is not limited to the number of reinforcement members used to secure the rods 32-35 in their fixed relationship, and the number of reinforcement members is dependent on the length of the rods, the length of the reinforcement members, and the orientation of the reinforcement members and the rods relative to one another. The orientation of the reinforcement members and the rods relative to one another is discussed in detail below. Each of the reinforcement members 37-41 has a four-sided configuration, e.g., a trapezoidal, a rectangular, or a square shape. Although in the following discussion the bars are arranged to have a four-sided configuration, the invention is not limited thereto and other configurations, e.g., a circle, oval, or ellipse can be made and used in the practice of the invention.

[0028] With continued reference to FIGS. 1-3 as needed, the reinforcement members 37-41 each include elongated segments 42, 43, 44, and 45 having their ends joined together in any usual manner, e.g., by welding to provide the reinforcement members 37-41 with a quadrilateral configuration having corners 50, 51, 52, and 53 as shown clearly in FIG. 1. In the following discussion and in the claims, the reinforcement members 37-41 may also be referred to as “quadrilateral reinforcement members” or “QRMs”. Although not limiting to the invention, the rod 33 is secured at or adjacent the corner 51 of the QRMs 37-41; the rod 34 is secured at or adjacent the corner 52 of the QRMs 37-41; the rod 32 is secured at or adjacent the corner 50 of the QRMs 37-41; and the rod 35 is secured at or adjacent the corner 53 of the QRMs 37-41. In the non-limiting embodiment of the support element 30, the QRMs 37-41 are arranged in an alternating fashion such that one side of each one of the adjacent ones of the QRMs 37-41 are closer together than the opposite side of the adjacent ones of the QRMs 37-41. More particularly and with reference to FIGS. 2 and 3 as needed, the QRM 37 has its member 43 and the corners 51 and 52 between the rods 33 and 34, and its member 45 and corners 50 and 53 between the rods 32 and 35; the adjacent QRM 38 has its member 45 and corners 50 and 53 between the rods 32 and 35, and its member 43 and corners 51 and 52 between the rods 33 and 34 with the member 43 of the QRMs 37 and 38 spaced a greater distance than the member 45 of the QRMs 37 and 38. The QRMs 37 and 38 provide a first reinforcement group of the support element 30. The QRM 39 has its member 43 and the corners 51 and 52 between the rods 33 and 34, and its member 45 and corners 50 and 53 between the rods 32 and 35 with the member 45 of the QRMs 38 and 39 spaced a greater distance than the member 43 of the QRMs 38 and 39; the adjacent QRM 40 has its member 45 and corners 50 and 53 between the rods 32 and 35 and its member 43 and corners 51 and 52 between the rods 33 and 34 with the member 45 of the QRMs 39 and 40 spaced a greater distance than the member 43 of the QRMs 39 and 40. The QRMs 39 and 40 provide a second reinforcement group of the support element 30. The foregoing spacing relationship continues for the QRMs 40 and 41 along the length of the support element 30 and any additional reinforcement group that may be added to the support element 30. In FIGS. 2 and 3, the QRM 41 is a QRM of the third reinforcement group of the support element 30.

[0029] With the above arrangement and as shown in FIG. 1, the rods 32 and 35 each lie in a first imaginary plane IP1, the rods 32 and 33 each lie in a second imaginary plane IP2, the rods 33 and 34 each lie in a third imaginary plane IP3, and the rods 34 and 35 each lie in a fourth imaginary plane IP4. As shown in FIG. 1 but not limiting to the invention, the first imaginary plane IP1 is spaced from and substantially parallel to the third imaginary plane IP3, the second imaginary plane IP2 is spaced from and substantially parallel to the fourth imaginary plane IP4, and the first imaginary plane IP1 and the third imaginary plane IP3 are each substantially perpendicular to the second imaginary plane IP2 and the fourth imaginary plane IP4. The reinforcement members 37-41 each lie in a plane that subtends an angle &agr; with imaginary planes IP1 and IP3 as shown in FIG. 3 in the range of greater than 0° to 90°, and a right angle with imaginary planes IP2 and IP4. The angle &agr; is not limiting to the invention and may be the same or different for each reinforcement member 37-41. Although not limiting to the invention, the angle &agr; is in the range of greater than 0° and less than 90°, preferably in the range of 30° to 60°, and more preferably 45°. As is appreciated by those skilled in the art, the angle &agr; has a complementary angle on the other side of the reinforcement member.

[0030] Although any side of the support element 30 may be used to support a load, the support element 30 has a higher load capacity with the rods 32 and 33 (IP2), and rods 34 and 35 (IP4) supporting (IP2 and IP4 normal to) the load than with the rods 32 and 35 (IP1), and 33 and 34 (IP3) supporting (IP1 and IP3 normal to) the load.

[0031] The rods 32-35 and the reinforcement members 37-41 are preferably rigid, solid rods made from a structurally stable material, such as metal, e.g., steel, coated steel, fiberglass reinforced plastic, aluminum, or laminated wood. In the practice of the invention, the rods 32-35 are preferably made of steel round stock and the reinforcement members 37-41 are preferably made of rebars because rebars have a patterned surface for the cement to adhere. In the instance when the support element is used in a corrosive, e.g., damp, environment, the support element may be coated with epoxy and/or zinc-iron to prevent rusting of the rebars. As can be appreciated by those skilled in the art, the invention is not limited to the material or surface of the rods and/or reinforcement members, and the rods 32-35 and/or the reinforcement members 37-41 may be made of solid bars having a smooth or patterned surface and/or structurally stable hollow bars having a smooth or patterned outer surface. Although the invention is not limiting to the number of QRMs used to maintain the rods in a fixed relationship to one another, a sufficient number of QRMs should be used for ease of handling the support elements, e.g., at least two QRMs, to minimize flexing of the rods 32-35.

[0032] As can now be appreciated, the invention is not limited to the dimensions of the rods 32-35, of the QRMs, or of the segments 42-45 of the QRMs. More particularly, the length of the support element 30 should be sized such that the support element 30 is manageable during transportation and moving into position to support a load. Lengths of 12 to 15 feet (3.65 to 4.57 meters) are usually manageable. Consider now the structural stability of the support element 30. As the load on the rods 32-35 increases, and the material of the rods and the dimension and material of the QRMs and the position of the QRMs to the rods is maintained constant, increasing the cross-sectional area, e.g., diameter of the rods 32-35, increases the load bearing capabilities of the support element 30 and vice versa. As the load on the rods 32-35 increases, and the dimension of the rods and the dimension and material of the QRMs and the position of the QRMs to the rods is maintained constant, increasing the structural stability of the material of the rods 32-35 increases the load bearing capabilities of the support element 30 and vice versa. The invention is not limited to the cross-sectional area of the rods or the structural stability of the material of the rods, however, as can be appreciated by those skilled in the art, the cross-sectional area and structural stability of the material should be sufficient to support the maximum expected load to be supported. As the load on the rods 32-35 increases, and the dimensions and material of the rods and the material of the QRMs and the position of the QRMs to the rods is maintained constant, increasing the length of the segments 43 and 45 while keeping the length of the segments 42 and 44 constant, or decreasing the length of the segments 42 and 44 while keeping the length of the segments 43 and 54 constant, increases the load bearing capabilities of the support element 30 and vice versa. As the load on the rods 32-35 increases, and the dimensions and material of the rods and the dimension of the QRMs and the position of the QRMs to the rods is maintained constant, increasing the structural stability of the material of the segments of the QRMs increases the load bearing capabilities of the support element 30 and vice versa. As the load on the rods 32-35 increases, and the dimension and material of the rods and the dimension and material of the QRMs is maintained constant, decreasing the distance between the QRMs, e.g., the distance between sides 45 of the QRMs and the distance between sides 43 of the QRMs, increases the load bearing capabilities of the support element 30 and vice versa. In regards to the angle &agr;, decreasing the angle &agr; while keeping the distances between the rods constant, increases the length of the reinforcement members and increases the distance between the sides of the reinforcement members, e.g., sides 43 of the reinforcement members 37 and 38 shown in FIGS. 2 and 3. Therefore, decreasing the angle &agr; reduces the number of reinforcement members securing the rods together and decreases the load bearing capacity of the support element 30.

[0033] As previously discussed, the support element 30 has a higher load bearing capacity with the rods 32 and 33, and 34 and 35 supporting the load, i.e., planes IP2 and IP4 normal to the load, than having the rods 32 and 35, and 33 and 34 supporting the load, i.e., the planes IP1 and IP3 normal to the load. Shown in FIGS. 4, 5, and 6 is support element 56 having load-bearing capacity with any one of the pair of rods supporting the load, i.e., with any one of the imaginary planes normal to the load. With reference to FIGS. 4-6 as needed, the rods 32-35 are held in a fixed relationship by a plurality of reinforcement members arranged in a sequence having the adjacent reinforcement member rotated 90°. More particularly, the reinforcement members 37, 39, and 41 are mounted between the rods 32-35 as previously discussed and shown in FIGS. 2 and 3. The reinforcement members 38 and 40 are replaced with reinforcement members 59 and 60. The reinforcement members 59 and 60 are similar in construction to the reinforcement members 38 and 40 with the difference being their orientation relative to the adjacent reinforcement members and the rods.

[0034] The reinforcement members 37 and 59 are a first reinforcement group of the support element 56. The reinforcement members 39 and 60 are a second reinforcement group of the support element 56. The reinforcement member 41 is one of the reinforcement members of the third reinforcement group of the support element 56. As can now be appreciated, the invention is not limited to the number of reinforcement groups used to maintain the rods 32-35 of the support element 56 in spaced relationship to one another.

[0035] Each of the reinforcement members 59 and 60 includes elongated segments 62-65 joined at their ends to form corners 68-71, as shown in FIGS. 4-6. More particularly, the segment 63 is connected to the segment 62 at the corner 69 and to the segment 64 at the corner 70, and the segment 65 is connected to the segment 62 at the corner 68 and to the segment 64 at the corner 71. The segment 62 and corners 68 and 69 are between the rods 32 and 33, and the segment 64 and corners 70 and 71 are between the rods 34 and 35. As shown in FIG. 6, the reinforcement members 37, 39, and 41 each lie in a plane that is normal to the imaginary planes IP2 and 1P4 and at the angle &agr; to the imaginary planes IP3 and IP1. The reinforcement members 59 and 60 each lie in a plane that is normal to the imaginary planes IP1 and IP3 and at an angle B with the imaginary planes IP2 and IP4. As can be appreciated, the invention contemplates that the angles &agr; and B may be equal to one another or different from one another. In the practice of the invention, it is preferred, although not limiting to the invention, that the angles &agr; and B are equal to one another. In this manner, the support element 56 has essentially the same load capacity regardless of what imaginary plane is normal to the load.

[0036] As can now be appreciated, the concepts of the support elements 30 and 56 can be combined. In one non-limiting embodiment and with reference to FIGS. 2 and 5, the reinforcement member 59 can be positioned between the reinforcement members 37 and 38; the reinforcement member 60 can be positioned between the reinforcement members 38 and 39; and a reinforcement member similar to the reinforcement members 59 and 60 can be positioned between the reinforcement members 39 and 40 and between reinforcement members 40 and 41. In another non-limiting embodiment of the invention and with reference to FIG. 5, one of the reinforcement members 59 or 60 may be rotated clockwise 90° as viewed in FIG. 5 to provide a spacing relationship and orientation similar to that shown in FIG. 3.

[0037] The discussion above regarding the range of degrees of the angle &agr; is applicable for the angle B. Further, the discussion regarding increasing the load bearing capacity of the support element 30 is applicable to increasing the load bearing capacity of the support element 56 and any variations thereof.

[0038] Shown in FIGS. 7 and 8 is support element 75 incorporating features of the invention. The support element 75 includes the rods 32-35 arranged in the imaginary planes IP1-1P4 in a manner to be discussed below. It should be noted that for ease of discussion, the imaginary planes IP1-1P4 of the support element 75 shown in FIG. 7 are made up of the same rods as the imaginary planes of the support element 30 of FIG. 1; the difference is that the rods 32-35 and the imaginary planes of FIG. 1 are rotated clockwise 90° as shown in FIG. 7. The rods 32-35 are spaced from one another by reinforcement members 78-80. Each of the reinforcement members 78-80 includes elongated segments 82-85 having their ends joined together to provide the reinforcement members with corners 88-91. The corners 88-91 are radiused to illustrate another non-limiting embodiment of the invention. The rods 32-35 are secured to the corners 88-91 respective in any usual manner, e.g., by welding. The reinforcement members 78-80 are secured to the rods 32-35 in an orientation similar to the orientation of the reinforcement members 37-41 shown in FIG. 3.

[0039] With reference to FIG. 7, to provide additional structural support to maintain the rods in position when the load is normal to the imaginary planes IP1 and IP3, the support element 75 further includes side braces 94 and 95 secured to outer surface portions of the rods 32 and 33, and 34 and 35, respectively. Each of the side braces 94, 95 has elongated segments 96-99 having their ends joined together to provide the side braces 94, 95 with a quadrilateral configuration having corners 101-104. The corners 101-104 are shown as radiused; however, as can be appreciated, the invention is not limited thereto and the corners may be squares, as shown for the reinforcement member 37 shown in FIG. 1.

[0040] With reference to FIG. 8, the adjacent reinforcement members 78 and 79, and 79 and 80 are spaced from one another a distance greater than the length of the side brace mounted between adjacent reinforcement members. The side braces may be opposite one another, e.g., secured to the outer surface portion of the rods 32 and 33, and to the outer surface portion of the rods 34 and 35, or the side braces may alternate with a side brace on one side of the support member, e.g., to the outer surface of the rods 32 and 33 and no brace on the opposite side, e.g., on the outer surface portion of the rods 32 and 33. Further, a side brace does not have to be between adjacent reinforcement members, e.g., side braces are mounted between groups of two or more reinforcement members.

[0041] The reinforcement members 78 and 79, and side braces 94 and 95 are one reinforcement group of support element 75 and reinforcement group 80 is a reinforcement member of the next reinforcement group of the support element 75. The reinforcement group of the support element 75 is repeated for the length of the support element 75.

[0042] FIGS. 9-12 show additional non-limiting embodiments of support elements having various combinations of side braces and reinforcement members. The end view of the support elements of FIGS. 9-12 are similar to the end view of support element 75 shown in FIG. 7.

[0043] In FIG. 9, the support element 110 has the reinforcement members 78-80 closer together than the arrangement shown in FIG. 8. The side braces 94-96 are arranged between adjacent reinforcement members and alternating from one side of the support element to the opposite side. More particularly, the side brace 94 is in the space between the reinforcement members 78 and 79 and secured to the outer surface portions of the rods 32 and 33. Moving to the right of the reinforcement member 79 as viewed in FIG. 9, the next side brace 95 is in the space between the reinforcement members 79 and 80 and secured to the outer surface portions of the rods 34 and 35. Moving to the right of the reinforcement member 80 as viewed in FIG. 9, the next side brace 96 is in the space between the next two reinforcement members (only reinforcement member 80 shown in FIG. 9) and secured to the outer surface portions of the rods 32 and 34. The reinforcement members 78 and 79, and side braces 94 and 95 form one reinforcement group of the support element 110. The reinforcement group of support element 110 shown in FIG. 9 is repeated for the length of the support element 110. In FIG. 9, reinforcement member 80 and side brace 96 are part of the second reinforcement group of the support element 110.

[0044] In FIG. 10 there is shown support element 112 having the reinforcement members 78-80 and 113. The reinforcement member 113 is similar to reinforcement member 79 in construction and mounting between the bars. In FIG. 10, the reinforcement members 78-80 and 113 are closer together such that a side brace overlays the adjacent sides of adjacent reinforcement members. As shown in FIG. 10, the side brace 95 is secured to the outer surface portions of the rods 34 and 35 and overlays the reinforcement members 78 and 79; the side brace 94 is to the right of the side brace 95, as viewed in FIG. 10, and is secured to the outer surface portions of the rods 32 and 33 and overlays portions of adjacent reinforcement members 79 and 80; the side brace 96 is to the right of the side brace 94, as viewed in FIG. 10 and is secured to the outer surface portions of the rods 32 and 33 and overlays portions of the reinforcement members 80 and 113. The reinforcement members 78, 79, 80, and 113 and side braces 94, 95, and 96 are one reinforcement group of the support element 112. The reinforcement group shown in FIG. 10 is repeated for the length of the support element 112. More particularly, side brace 114 overlapping portions of reinforcement member 78 is a part of the reinforcement group of the support element 112 to the left of reinforcement member 78 as shown in FIG. 10, and side brace 115 overlapping portions of reinforcement member 113 is part of the reinforcement group of the support element 112 to the right of reinforcement member 112 as shown in FIG. 10.

[0045] With reference to FIG. 11, there is shown support element 116 having the reinforcement members 78-80 oriented and spaced as shown in FIG. 8 with a side brace between adjacent reinforcement members and secured to outer surface portions of the rods 34 and 35. More particularly, the side brace 95 is between the reinforcement members 78 and 79, and the side brace 118, similar in construction to the side brace 95, is between the reinforcement rods 79 and 80. The side brace 95 is secured to the outer surface portions of the rods 32 and 33 and the side brace 118 is mounted to the inner surface portion of the rods 32 and 33. As can be appreciated, because the spacing between adjacent reinforcement members is greater than the length of the side braces, the side braces may both be mounted to the outer surface portions or to the inner surface portions of the rods 32 and 33. The reinforcement members 78 and 79 and the side braces 95 and 118 make one reinforcement group of the support element 116. The reinforcement member 80 is a part of the next reinforcement group of the support element 116. The side braces of the reinforcement groups of the support element 116 may all be secured to the outer or inner surface portions of the rods 34 and 35, or may be all on the inner or outer side portions of the rods 32 and 33, or may alternate from the side portions of the rods 34 and 35 to the side portions of the rods 32 and 33.

[0046] With reference to FIG. 12, there is shown support element 120 incorporating features of the invention. The support element 120 is similar to the support element 112 shown in FIG. 10 with the following differences. The reinforcement group of FIG. 12 has the side braces on the outer surface portion of the rods 34 and 35 and the side brace overlapping the portions of the reinforcement members 79 and 80 at their side closest to one another. The reinforcement group of support element 120 includes the side braces 94-96 and the reinforcement members 79, 80, 113, and 122. The reinforcement groups of support element 120 may be repeated along the length of the support element, or the reinforcement group may alternate between the outer surface of the rods 34 and 35 or the outer surface of the rods 32 and 33, or may have a number of reinforcement groups on the outer surface of the rods 34 and 35 before providing reinforcement groups on the other side of the support member.

[0047] While the invention is described in detail herein, it will be appreciated by those skilled in the art that various modifications and alternatives to the arrangements can be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements described above are illustrative only and are not limiting as to the scope of the invention, which is to be given the full breadth of the appended claims and any and all equivalents thereof.

Claims

1. A support element, comprising:

a first rod;

a second rod spaced apart from the first rod and positioned parallel to the first rod;

a third rod spaced apart from the first rod and the second rod and positioned parallel to the first rod and the second rod;

a fourth rod spaced apart from the first rod, the second rod, and the third rod, and positioned parallel to the first rod, the second rod, and the third rod,

wherein

the first rod and the second rod each lie in a first imaginary plane,

the second rod and the third rod each lie in a second imaginary plane,

the third rod and the fourth rod lie in a third imaginary plane,

the first rod and the fourth rod lie in a fourth imaginary plane, and

the first rod, the second rod, the third rod, and the fourth rod define a quadrilateral cross-sectional shape; and

a first reinforcement member connected to the first rod, the second rod, the third rod, and the fourth rod, the first reinforcement member having a first segment, a second segment connected substantially perpendicular to one end of the first segment, a third segment connected substantially perpendicular to one end of the second segment, and a fourth segment joining the first segment to the third segment,

wherein

the first reinforcement member is positioned inside and attached to the first rod, the second rod, the third rod, and the fourth rod, substantially perpendicular to the first imaginary plane and the third imaginary plane, and preferably at an angle with respect to the second imaginary plane and the fourth imaginary plane.

2. The support element as claimed in claim 1, further comprising a second reinforcement member provided inside and attached to the first rod, the second rod, the third rod, and the fourth rod, wherein the second reinforcement member is spaced away from the first reinforcement member.

3. The support element as claimed in claim 1, further comprising a second reinforcement member provided inside and attached to the first rod, the second rod, the third rod, and the fourth rod, wherein the second reinforcement member is positioned substantially perpendicular to the first imaginary plane and the fourth imaginary plane and preferably forms the same angles with respect to the second imaginary plane and the fourth imaginary plane as the first reinforcement member.

4. The support element as claimed in claim 1, further comprising a second reinforcement member positioned parallel to the first imaginary plane and connected to the first rod and the second rod.

5. The support element as claimed in claim 1, further comprising a second reinforcement member, a third reinforcement member, a fourth reinforcement member, and a fifth reinforcement member; the second reinforcement member, third reinforcement member, fourth reinforcement member, and fifth reinforcement member are positioned inside and attached to the first rod, the second rod, the third rod, and the fourth rod, wherein the third reinforcement member and the fifth reinforcement member are each positioned substantially perpendicular to the first imaginary plane and the third imaginary plane and preferably form the same angles with respect to the second imaginary plane and the fourth imaginary plane as the first reinforcement member, and the second reinforcement member and the fourth reinforcement member are each positioned substantially perpendicular to the second imaginary plane and the fourth imaginary plane and form an angle with respect to the first imaginary plane and the third imaginary plane.

6. An article, comprising:

four longitudinal members defined as a first rod, a second rod, a third rod, and a fourth rod, wherein each of the rods having a longitudinal axis, and the longitudinal axes of the first and second rods lie in a first plane, the longitudinal axes of the second and third rods lie in a second plane, the longitudinal axes of the third and fourth rods lie in a third plane, and the longitudinal axes of the fourth and first rods lie in a fourth plane with the first and third planes parallel to one another and the second and fourth planes spaced from one another and intersect the first and third planes; and

a reinforcement member having marginal edge portions lying in a plane defined as a fifth plane, the reinforcement member secured to each of the rods with the fifth plane intersecting both the first and third planes at a predetermined angle defined as a first predetermined angle.

7. The article as claimed in claim 6, wherein the article is a support member, the reinforcement member is a first reinforcement member and further including a second reinforcement member having marginal edges lying in a plane defined as a sixth plane, the second reinforcement member secured to each of the rods with the sixth plane intersecting both the first and third planes at a predetermined angle defined as a second predetermined angle, wherein the distance between the fifth and sixth planes at the intersection of the first plane is different than the distance between the fifth and sixth planes at the intersection of the third plane.

8. The support member as claimed in claim 7, wherein the at least one of the fifth or sixth planes is normal to the first and third planes.

9. The support member as claimed in claim 8, wherein the fifth and sixth planes are each normal to the first and third planes.

10. The support member as claimed in claim 7, wherein the first predetermined angle and the second predetermined angle are each in the range of greater than 0 and less than 90° or greater than 90° and less than 180°.

11. The support member as claimed in claim 7, wherein the second and fourth planes are parallel to one another and normal to the first and second planes.

12. The support member as claimed in claim 11, wherein the distance between the first and third planes is substantially equal to the distance between the second and the fourth planes.

13. The support member as claimed in claim 11, wherein the distance between the first and third planes is different than the distance between the second and fourth planes.

14. The support member as claimed in claim 7, further including a support member defined as a first support member secured to the first and second rods and another support member defined as a second support member secured to the third and fourth rods.

15. The article as claimed in claim 6, wherein the article is a support member, the reinforcement member is a first reinforcement member and the fifth plane is normal to the first and third planes, and further including a second reinforcement member having marginal edges lying in a plane defined as a sixth plane, the second reinforcement member secured to each of the rods with the sixth plane normal to the second and fourth planes and intersecting both the first and third planes at a predetermined angle defined as a second predetermined angle.

16. The support member as claimed in claim 15, further including a third reinforcement member having marginal edges lying in a seventh plane, a fourth reinforcement member lying in an eighth plane, wherein the seventh plane is normal to the first and third planes and intersects the second and fourth planes at a third predetermined angle and the eighth plane is normal to the second and fourth planes and intersects the first and third planes at a fourth predetermined angle.

17. The support member as claimed in claim 16, wherein the fifth plane intersects the second and fourth planes at a fifth predetermined angle, the second reinforcement member is between the first and third reinforcement members and the third reinforcement member is between the second and fourth reinforcement members and the second and fourth predetermined angles are equal to one another and the third and fifth predetermined angles are equal to one another.

18. The support member as claimed in claim 17, wherein the second, third, fourth, and fifth predetermined angles are equal to one another.

19. The support member as claimed in claim 18, wherein the second, third, fourth, and fifth predetermined angles are in the range of greater than 0 and less than 90° or greater than 70° and less than 180°.

20. The support member as claimed in claim 15, further including a support member defined as a first support member secured to the first and second rods and another support member defined as a second support member secured to the third and fourth rods.